code: def test_limit_categories(self, category="cat0"):
      dataset = SqlIndexDataset(
          sqlite_metadata_file=METADATA_FILE,
          remove_empty_masks=False,
          pick_categories=[category],
          frame_data_builder_FrameDataBuilder_args=NO_BLOBS_KWARGS,
      )
  
      self.assertEqual(len(dataset), 50)
      for i in range(len(dataset)):
          self.assertEqual(dataset[i].sequence_category, category)
  
imports: import logging
  import os
  import unittest
  from collections import Counter
  import pkg_resources
  import torch
  from pytorch3d.implicitron.dataset.sql_dataset import SqlIndexDataset
label_desc: Use image node_id 4 for calling the TestSqlDataset obj's underlying member method code with example usage: obj.test_limit_categories(category) without return types